The i5-4210u CPU is pretty good for most games.
However, the Intel HD 4400 graphics core is pretty weak compared to dedicated graphic chips, but it can still be used to play many games at 1366x768 resolution and low or medium graphic settings... unless the game is very demanding.
You can click the following link for some games played on a Surface Pro 2. Very low demanding games like LoL is playable at 1920x1080 with very high settings, but very demanding games like Far Cry 4 seems unplayable.
https://www.youtube.com/user/microsoftsurfaceproG